Color throw

Discoloration of the liquid passing through a filtration or ion exchangemedia. It may be flushing from the media interstices of traces of colored organic reaction intermediates; or it could indicate the presence of metallic ions, humus, tannins, or industrial wastes. May also be produced by extended ?standing?, during which slowly soluble colored matter accumulates in the water. New ion exchangeresin may have some initial color throw.